1. Technical Field
The techniques described herein relate to a circularly polarized horn antenna and to antenna components including a circular polarizer having a step-shaped portion and a choke offset from the antenna aperture.
2. Discussion of Related Art
Conventional horn antennas are used for transmission and reception of radio waves. Radio waves are electromagnetic waves having a frequency within the range of about several Hz to several hundreds of GHz. A conventional horn antenna may include a slab polarizer having a pyramid-like or conical shape that tapers down to a point at the antenna aperture. One problem with such slab polarizers is that they are typically both long and heavy. Another problem with conventional horn antennas is that their beamwidth decreases as frequency increases.
One alternative to a horn antenna is a spiral antenna which can provide a frequency-independent beamwidth. However, when spiral antennas are designed to operate at frequencies that have a small corresponding wavelength, the size of the antenna winding may be so small that it is difficult to manufacture. Further, because the windings are so tight in such spiral antennas, electrical arcs may occur between the windings when exposed to high power electromagnetic environments. Another drawback of spiral antennas is that their gain is inherently less than that of horn antennas, particularly when spiral antennas are loaded with an absorber to enhance operational bandwidth.